Mercury-204 Determination by Emission Spectroscopy

1965 ◽  
Vol 19 (3) ◽  
pp. 87-89 ◽  
Author(s):  
F. M. Smith
Keyword(s):  
Coefficient Of Variation ◽  
Isotope Shift ◽  
Emission Spectroscopy ◽  
Electrodeless Discharge ◽  
Discharge Lamp ◽  
Isotope Concentration ◽  
Single Determination ◽  
Time Required

The determination of mercury-204 was made by using the isotope shift of the 3984 A mercury line excited by electrodeless discharge. Densitometric traces were made from film recordings of the 3984 A line and the areas under the component peaks were determined. Ratios of each of these areas to the sum of the areas from all the line components are plotted against the isotope concentration to produce a working curve. The coefficient of variation for this method is approximately 11 percent The time required for a single determination (after fabrication of the discharge lamp) is about two hours.

scholarly journals The determination of organic matter in air

1887 ◽  
Vol 41 (246-250) ◽  
pp. 238-247 ◽  
Keyword(s):  
Organic Matter ◽  
Oxalic Acid ◽  
Potassium Permanganate ◽  
Water Analysis ◽  
Distilled Water ◽  
Dilute Solution ◽  
Single Determination ◽  
Time Required

The Only methods hitherto proposed for determining the amount of organic matter in air are the two devised by the late Dr. Angus Smith (“Air and Rain”). According to the first of these methods, a defi­nite quantity of the air to be examined is slowly bubbled through a dilute solution of potassium permanganate of known strength until it is fully or considerably bleached,' and in the latter ease the amount of undecomposed permanganate determined by oxalic acid. In the second method a known volume of air is bubbled through distilled water, and the latter examined for free and albuminoid ammonia by Wanklyn and Chapman’s process for water analysis. These methods are open to one or more of the following objec­tions :— 1. The time required for a single determination is very considerable , and recessarily varies with the amount of organic matter present.

Spectrographic Determination of Fluorine in Standard Rocks

1970 ◽  
Vol 24 (3) ◽  
pp. 359-361 ◽  
Author(s):  
I. Schoenfeld
Keyword(s):  
Coefficient Of Variation ◽  
Published Data ◽  
Main Difficulty ◽  
Addition Method ◽  
Spectrographic Determination ◽  
Single Addition ◽  
Single Determination ◽  
The Difference ◽  
Working Standards

The dc spectrochemical method based on the emission of CaF bands has been adapted to the determination of fluorine in standard rocks. The main difficulty of the spectrochemical method, namely, the need to prepare suitable working standards for each sample, was circumvented by using the single addition method. In the excitation step the problem arising from the difference in the volatility of Ca and F, which results in nonuniform supply of these elements to the arc, was overcome by burning the samples in the Stallwood jet. The coefficient of variation for a single determination is about 15%. The results for 10 standard rocks are presented and compared with previously published data.

Capillary Discharge Lamp for the Direct Determination of Iodine by Flame Atomic Absorption Spectroscopy

1982 ◽  
Vol 36 (1) ◽  
pp. 22-25 ◽  
Author(s):  
M. D. Lowe ◽  
M. M. Sutton ◽  
O. E. Clinton
Keyword(s):  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Direct Determination ◽  
Capillary Discharge ◽  
Electrodeless Discharge ◽  
Discharge Lamp ◽  
Flame Atomic Absorption ◽  
Quartz Capillary

A simple and inexpensive iodine capillary discharge lamp has been developed. The spectrum of iodine was produced by maintaining a current-limited alternating current discharge in a helium-iodine vapor mixture flowing through a quartz capillary discharge tube. The performance of this spectral lamp as a source of resonance radiation for atomic absorption spectroscopy was evaluated using both unshielded and argon-shielded air-acetylene and nitrous oxide-acetylene flames. Sensitivities and detection limits for iodine obtained using the reported spectral source were found to compare favorably with data reported by other workers who used an electrodeless discharge lamp and a modified hollow cathode lamp.

THE ASSAY OF SECRETIN IN THE RAT

1968 ◽  
Vol 42 (4) ◽  
pp. 535-547 ◽  
Author(s):  
N. G. HEATLEY
Keyword(s):  
Flow Rate ◽  
Dose Response ◽  
Coefficient Of Variation ◽  
Clinical Unit ◽  
Highly Active ◽  
Single Determination ◽  
Basal Flow ◽  
Different Doses

SUMMARY Some characteristics of the pancreas of the rat relevant to the assay of secretin are described, including mean basal flow rate and output of bicarbonate, minute-by-minute changes in rate of flow after different doses of secretin, dose—response relationships, and quantitative differences between the sexes. The coefficient of variation for a single determination of secretin was found to be 15·6%. Highly active secretin had no ecbolic effect, but pure cholecystokininpancreozymin (CCK-PZ) had a strong hydrelatic action. It is therefore formally impossible to assay secretin accurately in the presence of unknown amounts of CCK-PZ. This limitation applied to the cat also. Possible remedies are discussed. Crude preparations of secretin hydrochloride of very low potency which have been used as standards since 1955 appear to have suffered no loss of activity over several years. The value of the Hammarsten Cat Unit and of the Clinical Unit which is based on it seems to be substantially different in 1967, compared with earlier values, when assayed in the rat.

Determination of Plasminogen in Human Plasma by the Lysis Time Method

1966 ◽  
Vol 16 (01/02) ◽  
pp. 001-017 ◽  
Author(s):  
W Berg ◽  
K Korsan-Bengtsen ◽  
J Ygge
Keyword(s):  
Human Plasma ◽  
Present Method ◽  
Blood Donors ◽  
Fibrinogen Concentration ◽  
Plasmin Activity ◽  
Time System ◽  
Lysis Time ◽  
High Dilutions ◽  
Single Determination

SummaryA one-stage lysis time system containing fibrinogen, streptokinase, thrombin, and a known, small amount of plasminogen was used to determine plasminogen in plasma.The known amount of plasminogen was added to the system in order to keep the lysis times relatively short when a highly diluted plasma was tested. High dilutions of plasma were used to reduce the influence of the plasma inhibitors.The calculation of the plasminogen concentration was made on the basis of the correlation: “plasminogen = fibrinogen/lysis time” which was valid in the system. The method allowed determination of plasminogen in plasma with varying fibrinogen concentrations, as the fibrinogen concentration in plasma was considered in the calculation.The presence of “spontaneous” plasmin activity in the plasma did not influence the plasminogen determination. Estimated by this method, the plasminogen content in plasma from 32 blood donors aged 25-45 years was 13.1 ±2.4 casein u/ml. The error of a single determination was 0.3 casein u/ml. The plasminogen content in plasma, determined with the present method, is about 3-4 times higher than the content found when a caseinolytic method is used.

Molar Absorptivity Values for Aflatoxins and Justification for Their Use as Criteria of Purity of Analytical Standards

1970 ◽  
Vol 53 (1) ◽  
pp. 96-101 ◽  
Author(s):  
J V Rodricks ◽  
L Stoloff ◽  
W A Pons ◽  
J A Robertson ◽  
L A Goldblatt
Keyword(s):  
Thin Layer ◽  
Statistical Study ◽  
Molar Absorptivity ◽  
Confidence Limits ◽  
Components Of Variance ◽  
Significant Difference ◽  
Single Determination ◽  
Comparison Measurements ◽  
Analytical Standards

Abstract Measurements of molar absorptivities in methanol were carried out by two laboratories on samples of anatoxins Bi and Gi prepared and purified independently in four laboratories and on samples of aflatoxins B2 and G2 prepared and purified independently in three laboratories. Molar absorptivities of pure aflatoxins Bi, B2, G1, and G2 in benzene-acetonitrile (98 + 2) were determined at two laboratories. With the exception of aflatoxin G2, no significant difference between aflatoxin samples could be demonstrated. Molar absorptivity values and absorbance ratios for each aflatoxin, based on these data, are given. Statistical 95% confidence limits were established for a single determination of molar absorptivity. A statistical study was made of the components of variance which contribute to the accuracy of the determination of molar absorptivity. A comparison of the fluorescence intensities of spots of various aflatoxin preparations, developed on silica gel-coated thin layer plates, with the amount of aflatoxin in each spotting solution as determined by absorbance measurements, demonstrated the validity of using absorbance and fluorescence comparison measurements for aflatoxin quantitation.

Based on Atomic Spectrometry for the Determination of Titanium Element in Molten Steel

2012 ◽  
Vol 622-623 ◽  
pp. 1528-1531
Author(s):  
Cui Hong Ma ◽  
Wei Qiang Zhang
Keyword(s):  
Molten Steel ◽  
Emission Spectroscopy ◽  
Atomic Emission ◽  
Lag Time ◽  
High Accuracy ◽  
Atomic Spectrometry ◽  
Atomic Emission Spectrometry ◽  
Emission Spectrometry ◽  
Important Significance

Atomic emission spectrometry with high accuracy, short lag time, and low detection limit, it has been widely applied in various fields. The application of atomic emission spectrometry in the converter steelmaking process has an important significance to improve the smelting of speed and steel quality. This article describes the principle of atomic emission spectroscopy (AES) analysis. Spectra obtained by the experimental for qualitative analysis, detected molten steel containing titanium element.

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